Attachment problems and foster kids

Thanks for all the feedback and suggestions. I’m definitely going to work on being more positive and use compliment sandwiches (positive-negative-positive) The reason I suspected she has an attachment disorder is that she has such distrust of adults and tries to control everyone. Possibly that’s because she has such a dysfunctional relationship with her mom and never really developed the kind of normal parent-child relationship due to neglect. I wonder if it’s more of a Trauma Bond with her mom than a real, secure bond. Or a Disrupted Attachment where as a baby her needs were only some times met and she’s learned she can’t count on a parent to care for her. Based on the Attachment Disorder Assessment Scale by Dave Ziegler, Ph.D, she has Moderate Attachment Disorder, but I’m not sure how far that is since there are other disorders that cause kids to be defiant and controlling. I want to get to the root of the problem, because dealing with the day-to-day issues becomes so overwhelming. We want to be able to do fun things with her, help her make friends and have a life besides obsessing over what’s happening with her mom. But there are two challenges: she doesn’t really want to do things with us and she manages to get into trouble so often. For example, we had plans to take her to see The Hobbit. But earlier in the day, something set her off and she started an argument with my 4 year old and called her names that included obscenities. We can’t reward her after she’s done something like that and she claimed she didn’t want to go anyways when we grounded her. Her grandmother has been using reward and consequence systems as recommended by her therapist in the beginning, but it’s gotten to the point where she knows that if she asks for anything, it’s going to be either used as carrot to try to get her to behave or taken away as a consequence. So she’s completely stopped telling us for anything she wants. She’s been stealing money out of her grandma’s purse when she knows she could earn an allowance fairly easily by doing helping her grandma around the house. If when I was her age I did what she’s been doing to my parents or my grandparents, I would be grounded for months. We don't want to reward her when she hasn't learned a lesson and doesn't care.